Effect of NASA Light-Emitting Diode Irradiation on Wound Healing

Abstract

Objective: The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing. Background Data: Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans. Materials and Methods: In vitro and in vivo (animal and human) studies utilized a variety of LED wavelength, power intensity, and energy density parameters to begin to identify conditions for each biological tissue that are optimal for biostimulation. Results: LED produced in vitro increases of cell growth of 140-200% in mouse-derived fibroblasts, rat-derived osteoblasts, and rat-derived skeletal muscle cells, and increases in growth of 155-171% of normal human epithelial cells. Wound size decreased up to 36% in conjunction with HBO in ischemic rat models. LED produced improvement of greater than 40% in musculoskeletal training injuries in Navy SEAL team members, and decreased wound healing time in crew members aboard a U.S. Naval submarine. LED produced a 47% reduction in pain of children suffering from oral mucositis. Conclusion: We believe that the use of NASA LED for light therapy alone, and in conjunction with hyperbaric oxygen, will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program. 305

Correlation between light transmission and permeability of human dentin

“…In the same study, comparison between LED light and laser light revealed that both illumination systems promoted an increase in fibroblast proliferation, confirming that LED light can be used as a substitute for the laser. Other in vitro studies have also found that light irradiation stimulates proliferation of different cell lines [14,[17][18][19].…”

“…Statistically significant difference (Wilcoxon, p<0.05) was observed between the two conditions However, although the mechanisms that guide the beneficial effects of LED light have been investigated in vitro, little is known about LED light transmission through the hard tissues of the body (e.g., bone, cartilage, enamel, dentin). Until now, several studies have referred only to the effects of light applied directly to different cell lines [14,[16][17][18][19]. It is important to obtain data about the effects of transdentinal illumination on the behavior of typical pulp cells because the light has to propagate through the dentin barrier to interact with the pulp cells during clinical application of phototherapy to reduce dental pain and/or accelerate tissue healing.…”

Effect of low level laser on sutured wound healing in rats

“…This inflammation is absolutely required to provide wound healing, although its long-term persistence is considered one of the most important reasons of delay in the healing process 12 . During the first days of healing, biological events such as formation of new capillary blood vessels associated with progressive deposition and remodeling of collagen fibers will culminate in a complete cicatricial repair of the injured area 13 .…”

Blue and red light combination LED phototherapy for acne vulgaris in patients with skin phototype IV

“…The beneficial effects of red light on the skin have been suggested by many studies [35][36][37][38][39][40][41][42][43][44][45]. It has been demonstrated by an in vitro study that red light influenced cytokine release from macrophages, which consequently stimulated fibroblast proliferation [35].…”

“…A series of comprehensive studies performed by Whelan et al [43][44][45] demonstrated that 670 nm LED treatment upregulated tissue regeneration genes and accelerated wound closure. Their study also showed that the expression of genes coding cytokines and their receptors was downregulated after red LED treatment.…”